Taiwan's Legislative Yuan, the island's parliament, is better known internationally for its punch-ups than for its political debate.

But that does not mean Saturday's parliamentary elections are an irrelevance.

Saturday's poll is an important indicator of Taiwanese opinion

The outcome, and who ultimately wins control of the Yuan, will have a significant effect on the fortunes of President Chen Shui-bian, and his main rival Lien Chan, the leader of the opposition Nationalists or Kuomintang (KMT).

"Up to now the president and his allies have not had a majority in the Legislative Yuan," said Joseph Wu, chairman of the Mainland Affairs Council, the body responsible for Taiwan's relations with Beijing.

"Chinese officials seem to enjoy more friendship with the opposition here, and since the opposition has a majority, the Chinese seem to be under the illusion that they need to build a long-term relationship with them. That has been causing trouble in Taiwan's relations with China," he said.

As a political appointee and close ally of the president, Mr Wu argued that the current situation had allowed officials in Beijing to bypass Mr Chen's Democratic Progressive Party (DPP).

"If the president is able to win a majority with his own party or with his allies," Mr Wu said, "then the Chinese will have to face the reality that they have to deal with the president if they want to deal with Taiwan at all."

The opposition KMT, not surprisingly, sees the situation rather differently.

"If the president's camp wins more than 50% of the seats then Beijing may become even more belligerent, thinking Taiwan's independence is a foregone conclusion," claimed Szu-yin Ho, a member of the KMT's Central Committee.

"Military action could be more likely," he warned.

Key policy initiatives

If President Chen wins control of the parliament, it will help his chances of achieving three major policy objectives over the next few months.

Firstly he needs the Legislative Yuan to support an arms deal with the United States worth around $18bn.

Any political party that fails to perform well in this election loses their chance for the next election as well, I believe

I-Chiu Liu, Chengchi University

Mr Chen argues that the military hardware is vital for the island's defence, but his plan is unlikely to get the KMT's support.

"Some purchases are necessary but not $18bn," said the KMT's Mr Ho. "If this goes ahead it will take too much money away from other budgets."

Secondly, the president has pledged to update the island's constitution.

Beijing has criticised the plans bitterly, arguing that they are a move towards independence.

"Victory this weekend will be interpreted as an endorsement for President Chen's plan to revise the constitution and hold a referendum," said Joseph Cheng, a politics professor at Hong Kong's City University.

"Such a development will certainly escalate tension across the Taiwan Straits, and may even provoke a military response from the Chinese leadership," he said.

Mr Chen's party does not currently have a majority in parliament

Finally there is the issue of reform of the Legislative Yuan itself. Earlier this year the parliament voted to cut the number of members by half from 2007.

The proposals still need to be endorsed by the National Assembly, and also put to a referendum. But whoever controls the Yuan after the weekend will be able to consolidate their position as details of the changes are thrashed out.

"The new Legislative Yuan will have the power to write new rules for new political games - for example drawing up the new districts for the next election," said I-Chiu Liu, director of the Election Study Centre at Taiwan's National Chengchi University.

"As a result, any political party that fails to perform well in this election loses their chance for the next election as well, I believe," he said.

KMT's decline

The stakes may be high for the president, but they are just as high for the old guard of the KMT leadership.

Lien Chan's party is anxious to gain ground in Saturday's poll

Chairman Lien has presided over three election defeats in the last four years, and his party is no longer the largest in parliament, although together with its allies it still hangs on to a slim majority.

In public, at least, Mr Lien is relatively cautious about the prospects for his party on Saturday.

"The margin will be quite narrow," he said. "It could be that neither of the major parties can gain a majority and we have to rely on independents to gain power."

"For the opposition, this is all about whether they can escape their decline," said Emile Sheng, Assistant Professor of Political Science at Taiwan's Soochow University.

"If they and their allies fail to get half the seats, they are entirely defeated and it will continue a pattern begun in 2000.

"However, if they can hold on to a majority it will show that people in Taiwan don't want to see them wiped out," he said.

But one thing is certain. Many people in Taiwan will be hoping that even if the election is close, there will be no repeat of the wrangling that followed the disputed presidential poll in March, when Mr Chen won by the narrowest of margins.

That way, whatever the result, those elected will be allowed to get on with the tasks in hand.